1. Field of the Invention
The present invention relates to an electronic wristwatch having a pressure sensor.
2. Description of the Related Art
A pressure sensor can be used as a depth or altitude meter. For example, a depth meter is an essential piece of equipment for divers. Various kinds of depth meters are available on the market. However, the depth meters are all separate items. Namely, there has been no scuba-diving or snorkeling wristwatch which has a depth meter integrally and functionally incorporated therein.
Known depth meters come in two types: a mechanical type, which can indicate the depth of diving but cannot perform other functions, such as recording of the diving time, warning of the diving time after a preset time elapses, and/or warning of the depth when deeper than a preset level, contributing to safe diving and an electronic type, which can also perform various functions such as those mentioned above. However, the electronic type depth meter is rather complex in construction which sometimes results in malfunctions during diving.
In providing a wristwatch which has a depth meter (or an altitude meter) integrally and functionally incorporated therein, it is very important to prevent the depth meter from interferring with the existing crown and existing pushbutton(s) for switching various functions provided on the periphery of a watch case and also to enable the indicated or displayed depth to be easily seen without decreasing the visible field of a dial of the watch. In addition to the above, since the depth meter senses pressure, the depth meter has to be able to correctly receive the pressure of the water, to fully resist it, and to be completely sealed so as not to allow the water and the water pressure to affect the internal movement, internal electronic devices, etc. of the watch.